Wireless local area network offloading through radio access network rules

ABSTRACT

Methods, systems, and devices are described for Wireless Local Area Network (WLAN) offloading through radio access network rules. In one embodiment of a method of wireless communication, a mobile device may determine that Radio Access Network (RAN) assistance information is unavailable, the RAN assistance information including a first set of thresholds for switching a Packet Data Network (PDN) connection of the mobile device from a WLAN to a Wireless Wide Area Network (WWAN). The mobile device may further access a second set of thresholds based at least in part on the determining, and the mobile device may determine to switch the PDN connection from the WLAN to the WWAN based at least in part on the second set of thresholds.

CROSS REFERENCES

The present application for patent claims priority to U.S. ProvisionalPatent Application No. 61/991,383 by Faccin et al., entitled “WirelessLocal Area Network Offloading Through Radio Access Network Rules,” filedMay 9, 2014, assigned to the assignee hereof, and expressly incorporatedby reference herein.

BACKGROUND

The following relates generally to wireless communication, and morespecifically to Wireless Local Area Network (WLAN) offloading throughRadio Access Network (RAN) rules. Wireless communications systems arewidely deployed to provide various types of communication content suchas voice, video, packet data, messaging, broadcast, and so on. Thesesystems may be multiple-access systems capable of supportingcommunication with multiple users by sharing the available systemresources (e.g., time, frequency, and power). Examples of suchmultiple-access systems include code-division multiple access (CDMA)systems, time-division multiple access (TDMA) systems,frequency-division multiple access (FDMA) systems, and orthogonalfrequency-division multiple access (OFDMA) systems.

Generally, a wireless multiple-access communications system may includea number of access points, each simultaneously supporting communicationfor multiple mobile devices or user equipment (UE). Different accesspoints may in some cases be associated with different access networks,including Wireless Wide Area Network (WWAN) access networks or WLANs.When a suitable WLAN is available for a UE, it may be desirable tooffload one or more Packet Data Network (PDN) connections of the UE fromthe WWAN to the WLAN in order to reduce the amount of traffic on theWWAN and/or free up bandwidth for other WWAN users. For example, if a UEis consuming a large amount of WWAN bandwidth (e.g., a user is watchinga video), it may be desirable to switch the UE to an available WLAN inorder to free up spectrum on the WWAN for other users.

In order for a UE to switch one or more PDN connections between the WWANand the WLAN, the WWAN and/or the WLAN may need to inform the UE whichPDN connections are offloadable, and may also need to provide rules andother information to the UE regarding when PDN connections should beoffloaded to the WLAN and when they should be switched back to the WWAN.This information may, however, need to be efficiently provided to the UEin order to reduce the overhead signaling for implementing the switchingback and forth of the PDN connections between the WLAN and the WWAN.

SUMMARY

The described features generally relate to one or more improved systems,methods, and/or apparatuses for WLAN offloading through RAN rules. Whena UE is using a WWAN for one or more PDN connections, the WWAN may, inone embodiment, determine a mode of operation of the UE and, based atleast in part on that determination, selectively send or bypass sendingan offloadability indicator corresponding to the one or more PDNconnections and/or RAN rules and RAN assistance information that may beneeded to determine whether and when to switch the one or more PDNconnections between the WWAN and WLAN. In another embodiment, the WWANmay always send offloadability indicators corresponding to PDNconnections and/or RAN rules and RAN assistance information to the UE,but the UE may only use this information if a certain PDN is offloadableto an available WLAN, and otherwise may store the information for lateruse. When a UE has offloaded all PDN connections to an available WLAN,the UE may detach from the WWAN, thereby precluding the UE fromreceiving information needed to determine when a PDN connection shouldbe switched back to the WWAN. Accordingly, in some embodiments, the UEmay access alternative information, not contemporaneously provided bythe WWAN and not specific to a given UE, for use in determining whetherand when to switch one or more PDN connections back to the WWAN. Also,after the UE detaches from the WWAN, one or more methods may be used tocause the UE to camp on a different WWAN relatively soon afterdetachment in order to reduce the probability of, for example,circuit-switched calls that may be missed if the UE is not attached toany WWAN.

A method of wireless communication is described, with the methodincluding determining, by a mobile device, that Radio Access Network(RAN) assistance information is unavailable, the RAN assistanceinformation comprising a first set of thresholds for switching a packetdata network (PDN) connection of the mobile device from a wireless localarea network (WLAN) to a wireless wide area network (WWAN). The methodalso includes accessing a second set of thresholds based at least inpart on the determining, and switching the PDN connection of the mobiledevice from the WLAN to the WWAN based at least in part on the secondset of thresholds.

An apparatus for wireless communication is described, with the apparatusincluding means for determining that Radio Access Network (RAN)assistance information is unavailable, the RAN assistance informationcomprising a first set of thresholds for switching a packet data network(PDN) connection of the apparatus from a wireless local area network(WLAN) to a wireless wide area network (WWAN). The apparatus alsoincludes means for accessing a second set of thresholds based at leastin part on the determining, and means for switching the PDN connectionof the apparatus from the WLAN to the WWAN based at least in part on thesecond set of thresholds.

Another apparatus is described, with the apparatus including a processorand memory in electronic communication with the memory. The memoryembodies instructions, with the instructions executable by the processorto determine that Radio Access Network (RAN) assistance information isunavailable, the RAN assistance information comprising a first set ofthresholds for switching a packet data network (PDN) connection of theapparatus from a wireless local area network (WLAN) to a wireless widearea network (WWAN), access a second set of thresholds based at least inpart on the determining, and switch the PDN connection of the apparatusfrom the WLAN to the WWAN based at least in part on the second set ofthresholds.

A computer program product for communication by a wireless communicationapparatus in a wireless communication system is described. The computerprogram product includes a non-transitory computer-readable mediumstoring instructions executable by a processor to cause the wirelesscommunication apparatus to determine that Radio Access Network (RAN)assistance information is unavailable, the RAN assistance informationcomprising a first set of thresholds for switching a packet data network(PDN) connection of the apparatus from a wireless local area network(WLAN) to a wireless wide area network (WWAN), access a second set ofthresholds based at least in part on the determining, and switch the PDNconnection of the apparatus from the WLAN to the WWAN based at least inpart on the second set of thresholds.

In some examples of the method, apparatuses, and/or computer programproduct described above, the second set of thresholds may include one ormore of a connection quality indication (CQI) associated with the WLANand/or the WWAN, an Internet accessibility indication associated withthe WLAN and/or the WWAN, a signal strength indication associated withthe WLAN and/or the WWAN, and/or a power level associated with themobile device. The second set of thresholds may include a mobile devicespecific set of thresholds that was previously received by the mobiledevice from the WWAN, wherein the mobile device specific set ofthresholds is used in said determining if the mobile device specific setof thresholds has not expired.

In some examples of the method, apparatuses, and/or computer programproduct described above, the second set of thresholds may include adefault set of thresholds preconfigured in the mobile device, and thedefault set of thresholds may be set to values sufficiently high inorder to reduce a likelihood that the mobile device will switch the PDNconnection back to the WLAN within a predetermined time period afterswitching to the WWAN.

In some examples of the method, apparatuses, and/or computer programproduct described above, the second set of thresholds may include abroadcast set of thresholds provided by the WWAN, the broadcast set ofthresholds being unspecific to the mobile device, and the method mayfurther include receiving the broadcast set of thresholds via a systeminformation block (SIB) form the WWAN.

In some examples of the method, apparatuses, and/or computer programproduct described above, the method may further include receiving anindication instructing the mobile device to camp on a Radio AccessTechnology (RAT) associated with the WWAN if all PDN connections areoffloaded to the WLAN and a cellular radio of the mobile device is inidle mode, and the indication may include a RAT/Frequency SelectionPriority (RFSP) index value prioritizing connection of the mobile deviceto the RAT. The RAT may be one of GERAN or UTRAN in order to reduce aprobability of missing a circuit switched (CS) call at the mobiledevice, or the RAT may be UTRAN in order to allow the mobile device tocontinue receiving RAN assistance information related to the WWAN.

A method for wireless communication is described, with the methodincluding receiving, at a mobile device, an offloadability indicatorcorresponding to a packet data network (PDN) connection of the mobiledevice, the offloadability indicator being received irrespective of amode of operation of the mobile device, utilizing the offloadabilityindicator to determine whether to offload the PDN connection from awireless wide area network (WWAN) to a wireless local area network(WLAN), the offloadability indicator being utilized when the mobiledevice receives radio access network (RAN) assistance information orwhen the mobile device has access to a set of thresholds related tooffloading the PDN connection from the WWAN to the WLAN, anddisregarding the offloadability indicator when the mobile device is notreceiving RAN assistance information or when the mobile device does nothave access to a set of thresholds for use in making an offloadingdetermination.

An apparatus for wireless communications is described, with theapparatus including means for receiving an offloadability indicatorcorresponding to a packet data network (PDN) connection of theapparatus, the offloadability indicator being received irrespective of amode of operation of the apparatus, means for utilizing theoffloadability indicator to determine whether to offload the PDNconnection from a wireless wide area network (WWAN) to a wireless localarea network (WLAN), the offloadability indicator being utilized whenthe apparatus receives radio access network (RAN) assistance informationor when the apparatus has access to a set of thresholds related tooffloading the PDN connection from the WWAN to the WLAN, and means fordisregarding the offloadability indicator when the apparatus is notreceiving RAN assistance information or when the apparatus does not haveaccess to a set of thresholds for use in making an offloadingdetermination.

Another apparatus is described, with the apparatus comprising aprocessor and memory in electronic communication with the processor. Thememory embodies instructions, the instructions being executable by theprocessor to receive an offloadability indicator corresponding to apacket data network (PDN) connection of the apparatus, theoffloadability indicator being received irrespective of a mode ofoperation of the apparatus, utilize the offloadability indicator todetermine whether to offload the PDN connection from a wireless widearea network (WWAN) to a wireless local area network (WLAN), theoffloadability indicator being utilized when the apparatus receivesradio access network (RAN) assistance information or when the apparatushas access to a set of thresholds related to offloading the PDNconnection from the WWAN to the WLAN, and disregard the offloadabilityindicator when the apparatus is not receiving RAN assistance informationor when the apparatus does not have access to a set of thresholds foruse in making an offloading determination.

A computer program product for communication by a wireless communicationapparatus in a wireless communication system is described. The computerprogram product includes a non-transitory computer-readable mediumstoring instructions executable by a processor to cause the wirelesscommunication apparatus to receive an offloadability indicatorcorresponding to a packet data network (PDN) connection of theapparatus, the offloadability indicator being received irrespective of amode of operation of the apparatus, utilize the offloadability indicatorto determine whether to offload the PDN connection from a wireless widearea network (WWAN) to a wireless local area network (WLAN), theoffloadability indicator being utilized when the apparatus receivesradio access network (RAN) assistance information or when the apparatushas access to a set of thresholds related to offloading the PDNconnection from the WWAN to the WLAN, and disregard the offloadabilityindicator when the apparatus is not receiving RAN assistance informationor when the apparatus does not have access to a set of thresholds foruse in making an offloading determination.

In some examples of the method, apparatuses, and/or computer programproduct described above, the method may further include storing theoffloadability indicator for later use even if the mobile device is notreceiving RAN assistance information and/or does not have access to anythresholds for use in making the offloading determination, and furthermay include utilizing the offloadability indicator to determine whetherto offload the PDN connection to the WLAN when the mobile deviceswitches to a new RAT associated with the WWAN that does provide RANassistance information to the mobile device.

In some examples of the method, apparatuses, and/or computer programproduct described above, the offloadability indicator may be specific toa RAT over which the offloadability indicator was received, in whichcase the method may further include receiving an updated offloadabilityindicator corresponding to a different RAT when the mobile deviceswitches to the different RAT. In some examples of the method,apparatuses, and/or computer program product described above, theoffloadability indicator may be generic to a plurality of RATs and isreceived over a first RAT of the plurality of RATs, in which case themobile device may not receive a new offloadability indicator uponswitching to a second RAT of the plurality of RATs. The method mayfurther include storing the offloadability indicator for later use, evenif the first RAT does not provide RAN assistance information.

A method for wireless communication is described, with the methodincluding determining a mode of operation of a mobile device, andsending an offloadability indicator corresponding to a packet datanetwork (PDN) connection based at least in part on the determination.

An apparatus for wireless communication is described, with the apparatusincluding means for determining a mode of operation of a mobile device,and means for sending an offloadability indicator corresponding to apacket data network (PDN) connection based at least in part on thedetermination.

Another apparatus is described, with the apparatus comprising aprocessor and memory in electronic communication with the processor. Thememory embodies instructions, the instructions being executable by theprocessor to determine a mode of operation of a mobile device, and sendan offloadability indicator corresponding to a packet data network (PDN)connection based at least in part on the determination.

A computer program product for communication by a wireless communicationapparatus in a wireless communication system is described. The computerprogram product includes a non-transitory computer-readable mediumstoring instructions executable by a processor to cause the wirelesscommunication apparatus to determine a mode of operation of a mobiledevice, and send an offloadability indicator corresponding to a packetdata network (PDN) connection based at least in part on thedetermination.

In some examples of the method, apparatuses, and/or computer programproduct described above, the offloadability indicator may be sent to themobile device when the mobile device is in a mode in which WLANoffloading is permitted and/or the offloadability indicator may beselectively sent to a Radio Network Controller (RNC) when the mobiledevice is in an Iu mode of operation. Further, in some examples of themethod, apparatuses, and/or computer program product described above,the sending of the offloadability indicator may be bypassed when themobile device is in a mode in which WLAN offloading is not permitted,such as when the mobile device is in an A/Gb mode of operation. Also,said determining may be performed by a Serving General Packet RadioService Support Node (SGSN).

Further scope of the applicability of the described methods andapparatuses will become apparent from the following detaileddescription, claims, and drawings. The detailed description and specificexamples are given by way of illustration only, since various changesand modifications within the spirit and scope of the description willbecome apparent to those skilled in the art.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the presentinvention may be realized by reference to the following drawings. In theappended figures, similar components or features may have the samereference label. Further, various components of the same type may bedistinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If only the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

FIG. 1 shows a first block diagram of a wireless communications systemin accordance with various embodiments;

FIG. 2 shows a second block diagram of a wireless communications systemin accordance with various embodiments;

FIG. 3 shows a block diagram of a base station for use in offloading oneor more PDN connections in accordance with various embodiments;

FIG. 4 shows a block diagram of a base station for use in offloading oneor more PDN connections in accordance with various embodiments;

FIG. 5 shows a block diagram of a UE for use in offloading one or morePDN connections in accordance with various embodiments;

FIG. 6 shows a block diagram of a UE for use in offloading one or morePDN connections in accordance with various embodiments;

FIG. 7 shows a block diagram of a system for use in offloading one ormore PDN connections in accordance with various embodiments;

FIG. 8 shows a block diagram of a system for use in offloading one ormore PDN connections in accordance with various embodiments;

FIG. 9 shows an example of a signaling flow for use in offloading one ormore PDN connections in accordance with various embodiments;

FIGS. 10A and 10B provide examples of how one or more PDN connectionscan be offloaded to a WLAN in accordance with various embodiments;

FIGS. 11A and 11B provide examples of how one or more PDN connectionscan be offloaded to a WLAN in accordance with various embodiments;

FIGS. 12A and 12B provide examples of how one or more PDN connectionscan be offloaded to a WLAN in accordance with various embodiments;

FIGS. 13A and 13B provide examples of how one or more PDN connectionscan be offloaded to a WLAN in accordance with various embodiments;

FIGS. 14A and 14B provide examples of how one or more PDN connectionscan be offloaded to a WLAN in accordance with various embodiments;

FIGS. 15A and 15B provide examples of how one or more PDN connectionscan be moved to a different WWAN in accordance with various embodiments;

FIG. 16 shows a flowchart of a method for use in offloading one or morePDN connections in accordance with various embodiments;

FIG. 17 shows a flowchart of a method for use in offloading one or morePDN connections in accordance with various embodiments; and

FIG. 18 shows a flowchart of a method for use in offloading one or morePDN connections in accordance with various embodiments.

DETAILED DESCRIPTION

Features generally relating to one or more improved systems, methods,and/or apparatuses for offloading one or more PDN connections to a WLANare described. When a UE has one or more PDN connections with a WWAN,the WWAN may, in one embodiment, determine a mode of operation of the UEand, based at least in part on that determination, selectively send orbypass sending an offloadability indicator corresponding to the one ormore PDN connections and/or RAN rules and RAN assistance informationthat may be needed to determine whether and when to switch the one ormore PDN connections between the WWAN and WLAN. In another embodiment,the WWAN may always send offloadability indicators corresponding to PDNconnections and/or RAN rules and RAN assistance information to the UE,but the UE may only use this information if a certain PDN is offloadableand/or if a suitable WLAN is available, and otherwise may store theinformation for later use. If a UE offloads all PDN connections to aWLAN, the UE may detach from the WWAN, which might preclude the UE fromreceiving information needed to determine when a PDN connection shouldbe switched back to the WWAN. Accordingly, in some embodiments, the UEmay access alternative information, not contemporaneously provided bythe WWAN or not specific to the UE, for use in determining whether andwhen to switch one or more PDN connections back to the WWAN. Also, afterthe UE detaches from the WWAN, one or more policies may encourage orcause the UE to camp on a different WWAN relatively soon afterdetachment in order to reduce the probability of, for example,circuit-switched calls that may be missed if the UE is not attached toany WWAN.

Thus, the following description provides examples, and is not limitingof the scope, applicability, or configuration set forth in the claims.Changes may be made in the function and arrangement of elementsdiscussed without departing from the spirit and scope of the disclosure.Various embodiments may omit, substitute, or add various procedures orcomponents as appropriate. For instance, the methods described may beperformed in an order different from that described, and various stepsmay be added, omitted, or combined. Also, features described withrespect to certain embodiments may be combined in other embodiments.

Referring first to FIG. 1, a diagram illustrates an example of awireless communications system 100. The wireless communications system100 includes a plurality of access points such as base stations 105(which may be eNBs, NBs, etc.) and WLAN access points 140, a number ofmobile devices such as user equipments (UEs) 115, and a core network130. Some of the access points 105, 140 may communicate with the UEs 115under the control of a base station controller (not shown), which may bepart of the core network 130 or certain access points in variousexamples. Some of the access points 105, 140 may communicate controlinformation and/or user data with the core network 130 through backhaullinks 132. In some examples, some of the access points 105, 140 maycommunicate, either directly or indirectly, with each other overbackhaul links 134, which may be wired or wireless communication links.The wireless communications system 100 may support operation on multiplecarriers (waveform signals of different frequencies). Multi-carriertransmitters can transmit modulated signals simultaneously on themultiple carriers. For example, each communication link 125, 128 may bea multi-carrier signal modulated according to various radiotechnologies. Each modulated signal may be sent on a different carrierand may carry control information (e.g., reference signals, controlchannels, etc.), overhead information, data, etc.

The access points 105, 140 may wirelessly communicate with the UEs 115via one or more access point antennas. Each of the access points 105,140 may provide communication coverage for a respective geographiccoverage area 110. Some access points may provide access to one or moreWWANs, and these access points may be referred to as base stations 105,including base transceiver stations (BTS), radio base stations, radiotransceivers, basic service sets (BSS), extended service sets (ESS),NodeBs, evolved NodeBs (eNBs), Home NodeBs, Home eNodeBs, and so forth.In some embodiments, each such base station 105 may provide access toone or more Radio Access Technologies (RATs) associated with a WWAN.Other access points 140 may provide access to one or more WLANs, andthese access points may be referred to as WLAN access points 140,including WiFi routers and the like. In some embodiments, each WLANaccess point 140 may provide access to one or more RATs associated witha WLAN. Generally speaking, a WLAN may have a smaller geographiccoverage area 110 than a WWAN. For example, a WLAN's geographic coveragearea may extend ten meters to one hundred meters from the WLAN accesspoint 140, whereas a WWAN's geographic coverage area may extendthousands of meters from a base station 105. The coverage areas ofdifferent access points 105, 140 including the coverage areas of thesame or different types of access points 105, 140 utilizing the same ordifferent radio technologies, and/or belonging to the same or differentaccess networks, may overlap.

In some examples, the wireless communications system 100 may include anLTE/LTE-A communications system or network. In LTE/LTE-A communicationssystems, the term evolved Node B (eNB) may be generally used to describethe access points 105. The wireless communications system 100 may alsobe a Heterogeneous LTE/LTE-A network in which different types of eNBsprovide coverage for various geographical regions. For example, each eNB105 may provide communication coverage for a macro cell, a pico cell, afemto cell, and/or other types of cell. A macro cell generally covers arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs with service subscriptions withthe network provider. A pico cell would generally cover a relativelysmaller geographic area and may allow unrestricted access by UEs withservice subscriptions with the network provider. A femto cell would alsogenerally cover a relatively small geographic area (e.g., a home) and,in addition to unrestricted access, may also provide restricted accessby UEs having an association with the femto cell (e.g., UEs in a closedsubscriber group (CSG), UEs for users in the home, and the like). An eNBfor a macro cell may be referred to as a macro eNB. An eNB for a picocell may be referred to as a pico eNB. And, an eNB for a femto cell maybe referred to as a femto eNB or a home eNB. An eNB may support one ormultiple (e.g., two, three, four, and the like) cells.

The core network 130 may communicate with the access points 105, 140 viaa backhaul link 132 (e.g., S1, etc.). The access points 105, 140 mayalso communicate with one another, e.g., directly or indirectly viabackhaul links 134 (e.g., X2, etc.) and/or via backhaul links 132 (e.g.,through core network 130). The wireless communications system 100 maysupport synchronous or asynchronous operation. For synchronousoperation, the access points may have similar frame timing, andtransmissions from different access points may be approximately alignedin time. For asynchronous operation, the access points may havedifferent frame timing, and transmissions from different access pointsmay not be aligned in time. The techniques described herein may be usedfor either synchronous or asynchronous operations.

The UEs 115 may be dispersed throughout the wireless communicationssystem 100, and each UE 115 may be stationary or mobile. A UE 115 mayalso be referred to by those skilled in the art as a mobile device, amobile station, a subscriber station, a mobile unit, a subscriber unit,a wireless unit, a remote unit, a wireless device, a wirelesscommunication device, a remote device, a mobile subscriber station, anaccess terminal, a mobile terminal, a wireless terminal, a remoteterminal, a handset, a user agent, a mobile client, a client, or someother suitable terminology. A UE 115 may be a cellular phone, a personaldigital assistant (PDA), a wireless modem, a handheld device, a tabletcomputer, a laptop computer, a cordless phone, a wireless local loop(WLL) station, or the like. A UE may be able to communicate with macroeNBs, pico eNBs, femto eNBs, relays, and the like. A UE may also be ableto communicate over different access networks, such as cellular or otherWWANs or WLANs.

Taking the UE 115-a in FIG. 1 as an example, the communication link 125to the base station 105-a may include an uplink for carrying uplink (UL)transmissions (e.g., from UE 115-a to access point 105-a) and/or adownlink for carrying downlink (DL) transmissions (e.g., from accesspoint 105-a to UE 115-a). The UL transmissions may also be calledreverse link transmissions, while the DL transmissions may also becalled forward link transmissions. The communication link 128 from UE115-a to the WLAN access point 140 may similarly include an uplinkand/or a downlink.

The UEs 115 may in some embodiments simultaneously communicate with morethan one access point, including more than one different types of accesspoints. In some embodiments, a UE 115 such as the UE 115-a may managedata connectivity at the UE 115-a by determining that some or alltraffic of one or more PDN connections of the UE can or should beoffloaded to a WLAN (e.g., to the WLAN AP 140), and refraining fromtransmitting and receiving data over WWAN PDN connections (e.g., PDNconnections with the eNB 105-a). In response to detecting a triggeringevent, the UE 115-a may thereafter re-establish one or more PDNconnections with an available WWAN. The management of data connectivityat the UEs 115 is described in further detail below.

In systems, such as system 100, in which PDN connections can beoffloaded from a WWAN to a WLAN, and optionally can be switched back tothe WWAN, there are a number of aspects of such transfers that may ormay not need to be considered. For example, it may be important forcarriers using Circuit Switched Fall Back (CSFB) over LTE to be surethat a UE does not detach from an LTE connection when PDN connectionsare offloaded to WLAN—otherwise CSFB may not be available anymore. Asanother example, LTE RAN assistance information may only be available tothe UE if the UE remains attached to an LTE connection. When attached toa UTRAN connection, a UE may only receive 3G RAN assistance informationthat is not useful for steering traffic back to an LTE connection. Insome cases, no RAN assistance may be provided over a GERAN connectiondue to its semi-legacy status among the various RATs. Also, in someinstances, NAS signaling may be used to send an offloadability indicatorto a UE regardless of whether a PDN is offloadable or not—and thisoffloadability indicator may only be meaningful when the UE operates incertain modes of operation, but not in others. Still further, in someinstances, an SGSN may need to send an indicator from the SGSN to RAN inthe UE context, e.g., to allow the RNC to determine to which UE to sendthe RAN assistance in unicast RRC. If the UE does not receive RANassistance information in a GERAN connection, the SGSN may only send theinformation to an RNC, but not to the BSC in some embodiments. Stillfurther, in some instances, an Access Network Discovery and SelectionFunction (ANDSF) may not be available to provide information relating tothe offloading of PDN connections, and instead an operator may need torely on RAN signaling to communicate offloadability information. Theseconsiderations may only be applicable in certain implementations, andthey should not be read to be requirements of the appended claims.

Referring now to FIG. 2, a wireless communications system 200 is shown.The wireless communications system 200 includes a UE 115-b, an enhancedpacket core (EPC) 130-a, a 1×/HRPD packet core 130-b, as well as anumber of access points 105, 140, a number of controllers 205, a numberof gateways 210, and a number of PDNs 235. Some of the access points mayinclude a base station 105, such as an eNB base station 105-b associatedwith an LTE access network, a base station 105-c associated with aUTRAN, a base station 105-d associated with a GERAN, a WLAN access point140-a-1 associated with a first WLAN, a WLAN access point 105-a-2associated with a second WLAN, and so forth.

The enhanced packet core 130-a may include a number of devices 205-aimplementing Mobile Management Entities (MMEs) and Serving Gateways(SGWs). Alternatively, one or more of the MMEs and SGWs may beimplemented in separate devices. The SGWs may, in turn, be incommunication with one or more Packet Data Network Gateways (PDN-GWs)210-a-1, 210-a-2. Each of the PDN-GWs 210-a-1, 210-a-2 may be incommunication with one or more PDNs 235.

The eNB 105-a-1 may access the EPC 130-a through a direct connection tothe MME/SGW devices 205-a. The UTRAN BS 105-c may be in communicationwith a Radio Network Controller (RNC) 205-b, which in turn maycommunicate with a Serving GPRS Support Node (SGSN) 215 to access theEPC 130-a through MME/SGs 205-a. The first WLAN access point 140-a-1 maycommunicate with an evolved Packet Data Gateway (ePDG) 205-d, which mayprovide access to the EPC 130-a through the PDN-GWs 210-a. The secondWLAN AP 140-a-2 may bypass the EPC 130-a and may communicate directlywith the PDNs 235 through direct IP addressing. The GERAN BS 105-d maybe in communication with a BSC 205-e, which may be in communication witha core network 130-b (e.g., a 1×/HRPD core network). The core network130-b may be in communication with one or more of the PDNs 235.

Each of the eNB 105-b, UTRAN BS 105-c, and GERAN BS 105-d may provideaccess to a WWAN, whereas each of the WLAN APs 140-a-1, 140-a-2 mayprovide access to a WLAN. The eNB 105-a-1 may provide access to an LTEWWAN, whereas the UTRAN BS 105-c and GERAN BS 105-d may provide accessto non-LTE WWANs.

In some embodiments, a UE 115 such as the UE 115-b may establish PDNconnections with more than one of the eNB 105-b, UTRAN BS 105-c, GERANBS 105-d WLAN AP 140-a-1, WLAN AP 140-a-2, and/or other access points(e.g., the UE 115-b may support multi-access PDN connectivity (MAPCON)).PDN connections over different access networks may be established usingdifferent Access Point Names (APNs). In some embodiments, a UE 115 mayestablish or maintain PDN connections with more than one access pointsimultaneously.

A UE 115 such as the UE 115-b may have preferences for accessing accessnetworks to establish data connectivity. The preferences may be based onnetwork operator policies. Using the preferences, the UE 115-b mayestablish data connectivity over one or more available networks tomaintain data connectivity.

FIG. 3 shows a block diagram 300 of a base station 105-e for use inoffloading one or more PDN connections to a WLAN in accordance withvarious embodiments. The base station 105-e in FIG. 3 may be, forexample, one of the base stations 105, 105-a, 105-b, 105-c, 105-d shownin FIGS. 1 and 2. The base station 105-e shown in FIG. 3 includes areceiver 310, an offloading module 315, and a transmitter 320. The basestation 105-e may also include a processor. Each of these components maybe in communication with each other.

The components of the base station 105-e may, individually orcollectively, be implemented with one or more application-specificintegrated circuits (ASICs) adapted to perform some or all of theapplicable functions in hardware. Alternatively, the functions may beperformed by one or more other processing units (or cores), on one ormore integrated circuits. In other embodiments, other types ofintegrated circuits may be used (e.g., Structured/Platform ASICs, FieldProgrammable Gate Arrays (FPGAs), and other Semi-Custom ICs), which maybe programmed in any manner known in the art. The functions of each unitmay also be implemented, in whole or in part, with instructions embodiedin a memory, formatted to be executed by one or more general orapplication-specific processors.

The receiver 310 may receive information such as packets, user data,and/or control information associated with various information channels(e.g., control channels, data channels, etc.). Information may be passedon to the offloading module 315, and to other components of the basestation 105-e. For example, the receiver 310 may receive informationregarding when and which PDN connections with various UEs should beoffloaded to an available WLAN.

The offloading module 315 may be configured to provide offloadinginformation related to one or more PDN connections of one or more UEs115. For example, the offloading module 315 may be configured to providean offloadability indicator for each PDN connection of each UE 115 thatindicates whether that PDN connection can be offloaded to a WLAN ifavailable. The offloading module may also be configured to provide RANrules and RAN assistance information related to possible offloading ofPDN connections to WLAN and the reswitching of these PDN connectionsback to a WWAN associated with the base station 105-e.

The transmitter 320 may transmit one or more signals received from othercomponents of the base station 105-e. For example, the transmitter 320may transmit offloadability indicators corresponding to specific PDNconnections to one or more UEs using NAS signaling. In some embodiments,the offloadability indicators may be sent to the UEs from the EPC 130-a,with the determination of whether a specific PDN should or should not beoffloadable being made by one or more of an MME 205-a, an SGSN 215, aPolicy and Charging Rules Function (PCRF), etc.

The transmitter 320 may also transmit RAN rules and RAN assistanceinformation to the UEs. RAN rules may be a set of conditions under whicha PDN connection should be offloaded from a WWAN to a WLAN and/orswitched back to the WWAN. For example, one RAN rule may be that if asuitable WLAN signal is available, then a PDN connection shouldgenerally be offloaded to that WLAN. Another rule may be that if a WLANsignal strength is weak, but a suitably strong WWAN signal is available,a PDN connection currently being serviced through the WLAN should beswitched back to the WWAN. In some embodiments, RAN rules may cover themobility of a PDN connection to both the EPC 130-a (i.e., in a PDNconnection handover) and to a direct IP connection via a Non-SeamlessWLAN Offload (NSWO).

RAN assistance information may include thresholds as to when thesetransfers should happen. It will be appreciated that different accesspoints may have different thresholds at which one or more PDNconnections should be maintained or transferred to another access point.Therefore, whereas RAN rules define the general set of conditions underwhich such transfers should take place, the RAN assistance informationis specific to a base station and UE that has established or willestablish a PDN connection. In some embodiments, the transmitter 320 maybe co-located with the receiver 310 in a transceiver module. Thetransmitter may transmit packets and information over one or morewireless protocols—for example, LTE, WiFi, DSRC, and so forth.

Still referring to FIG. 3, in some embodiments the base station 105-e(e.g., the offloading module 315 or, alternatively, the SGSN 215) may beconfigured to determine a mode of operation of a UE 115, and, based atleast in part on the determination, send an offloadability indicatordescribed above that corresponds to a specific PDN connection. Forexample, in some embodiments, the offloadability indicator may be sentto the UE 115 only when the UE 115 is operating in a mode in which WLANoffloading is permitted (e.g., when the UE is in an Iu or LTE mode ofoperation). If, for example, the UE is in the Iu mode of operation andconnected to a UTRAN BS 105-c, the offloadability indicator may beprovided to the RNC 205-b shown in FIG. 2. The RNC and UTRAN BS 105-cmay utilize the received indicator to determine whether to send RANrules and/or RAN assistance information to a UE 115. In alternativeembodiments, the offloadability indicator may be provided to the UE 115for immediate use and/or to be stored for later use. The sending of theoffloadability indicator may, however, be bypassed if the UE 115 is in amode in which WLAN offloading is not permitted—such as if the UE 115 isan A/GB mode of operation with a GERAN BS 105-d.

FIG. 4 shows a block diagram 400 of a base station 105-f for use inoffloading one or more PDN connections to a WLAN in accordance withvarious embodiments. The base station 105-f may be, for example, one ofthe base stations 105, 105-a, 105-b, 105-c, 105-d, 105-e shown in FIGS.1-3, and may be an example of one or more aspects of the base station105-e described with reference to FIG. 2. The base station 105-f shownin FIG. 3 includes a receiver 310, an offloading module 315-a, and atransmitter 320. The base station 105-f may also include a processor.Each of these components may be in communication with each other. Theoffloading module 315-a in FIG. 4 includes an RFSP module 405, a SIBbroadcast module 410, and a NAS broadcast module 415.

The components of the base station 105-f may, individually orcollectively, be implemented with one or more application-specificintegrated circuits (ASICs) adapted to perform some or all of theapplicable functions in hardware. Alternatively, the functions may beperformed by one or more other processing units (or cores), on one ormore integrated circuits. In other embodiments, other types ofintegrated circuits may be used (e.g., Structured/Platform ASICs, FieldProgrammable Gate Arrays (FPGAs), and other Semi-Custom ICs), which maybe programmed in any manner known in the art. The functions of each unitmay also be implemented, in whole or in part, with instructions embodiedin a memory, formatted to be executed by one or more general orapplication-specific processors.

The receiver 310 may receive information such as packets, user data,and/or control information associated with various information channels(e.g., control channels, data channels, etc.), as described above withreference to FIG. 3. Information may be passed on to the offloadingmodule 315-a, and to other components of the base station 105-f. Theoffloading module 315-a may be configured to perform the operationsdescribed above with reference to the offloading module 315 shown inFIG. 3. The transmitter 320 may transmit the one or more signalsreceived from other components of the base station 105-f, as describedabove with reference to FIG. 3.

The RFSP module 405, the SIB broadcast module 410, and the NAS broadcastmodule 415 may all be configured to receive, provide, and/or analyzeinformation related to the connection of various UEs to a WWANassociated with the base station 105-f and/or their connection to a WLANAP 140. The RFSP module 405, for example, may provide RAN/FrequencySelection Priority index information, which may prioritize theconnection of a UE 115 to a specific Radio Access Technology (RAT), suchas GERAN, UTRAN, or LTE. In one embodiment, for example, the RFSP module405 may be configured to provide an indication to a UE 115 (through thetransmitter 320) to camp on a RAT associated with the WWAN of the basestation 105-f if all PDN connections are offloaded to a WLAN and acellular radio of the UE is thereby placed in idle mode. This mayprevent the UE 115 from unsuccessfully trying to connect to a specificRAT, such as LTE, many times over, and instead may cause the UE toreattach to a GERAN/UTRAN connection as fast as possible so as to reducethe likelihood of missing, for example, a CSFB incoming call. The RFSPmodule 405 may thus consider not only conventional factors in creatingthe RFSP index, but may also consider the offloading of PDNconnections—specifically, the RFSP index may be such that camping onUTRAN and/or GERAN is forced if a UE 115 offloads all PDN connections toa WLAN or not. In another embodiment, the UE 115 may read the RANassistance information before making a decision to reconnect to thecellular network. Reading the RAN assistance information beforereconnection may prevent ping ponging between WLAN and the cellularnetwork after having offloaded all of the traffic to the WLAN.

The SIB broadcast module 410 may be configured to provide offloadinginformation in the SIB broadcast message for the base station 105-f—suchas generalized RAN assistance thresholds. These generalized thresholdsmay not be specific to individual UEs 115, but may be used by certainUEs 115 if the UEs are not connected to a specific WWAN. The NASbroadcast module 415 may also be configured to provide offloadinginformation through NAS signaling. For example, the NAS broadcast module415 may provide offloadability indicators (e.g., to individual UEs 115)regarding whether each active PDN connection can be offloaded to a WLANor not.

FIG. 5 shows a block diagram 500 of a UE 115-c that may offload one ormore PDN connections to a WLAN in accordance with various embodiments.The UE 115-c in FIG. 5 may be, for example, one of the UEs 115, 115-a,115-b shown in FIGS. 1 and 2. The UE 115-c shown in FIG. 5 includes areceiver 310, a threshold module 505, and a transmitter 320. The UE115-c may also include a processor. Each of these components may be incommunication with each other. In some embodiments, the UE 115-c maysupport Voice Over LTE (VoLTE), whereas in other embodiments, the UE115-c may only support Circuit Switched (CS) or Circuit Switched FallBack (CSFB) calls.

The components of the UE 115-c may, individually or collectively, beimplemented with one or more application-specific integrated circuits(ASICs) adapted to perform some or all of the applicable functions inhardware. Alternatively, the functions may be performed by one or moreother processing units (or cores), on one or more integrated circuits.In other embodiments, other types of integrated circuits may be used(e.g., Structured/Platform ASICs, Field Programmable Gate Arrays(FPGAs), and other Semi-Custom ICs), which may be programmed in anymanner known in the art. The functions of each unit may also beimplemented, in whole or in part, with instructions embodied in amemory, formatted to be executed by one or more general orapplication-specific processors.

The receiver 310 may receive information such as packets, user data,and/or control information associated with various information channels(e.g., control channels, data channels, etc.). Information may be passedon to the threshold module 505, and to other components of the UE 115-c.In some embodiments, the receiver 310 may receive offloadabilityindicators, RAN rules, and/or RAN assistance information relating to theoffloadability of one or more active PDN connections that the UE 115-chas with either a base station 105 or a WLAN AP 140. In one example, thereceiver 310 may receive an indication (e.g., originating from the RFSPmodule 405 in FIG. 4) instructing the UE 115-c to camp on a certain RATassociated with a WWAN of a base station 105 if all PDN connections areoffloaded to an available WLAN and a cellular radio of the UE is putinto an idle mode. As mentioned above, this indication may prioritizeconnection of the UE to a specific RAT—for example, the indication mayprioritize a GERAN or UTRAN connection in order to reduce theprobability of the UE 115-c missing a telephone call over a CSFBconnection, or any other circuit switched information. Alternatively,the indication may prioritize a UTRAN connection in order to allow theUE 115-c to continue receiving RAN assistance information related to aWWAN of a base station 105 (if, for example, such RAN assistanceinformation is not provided over a GERAN RAT).

The threshold module 505 may be configured to receive, provide, and/oranalyze offloadability indicators, RAN rules, and/or RAN assistanceinformation (such as thresholds) and to determine whether and when toswitch certain PDN connections between a WWAN and a WLAN available tothe UE 115-c. In those cases with at least one active PDN connectionwith a WWAN, the threshold module 505 may receive current and UE 115-cspecific RAN assistance information from the base station 105 associatedwith the WWAN, and make the determination of whether certain PDNconnections should be switched to either the WLAN or back to the WWANbased on this current and UE-specific information. In other embodiments,however (many of which are described below), the UE 115-c may not haveaccess to current, UE-specific information, such as RAN assistanceinformation. This may be the case if, for example, all PDN connectionsof the UE 115-c have been offloaded to a WLAN AP 140, or if the onlyremaining PDN connection of the UE 115-c is on a GERAN RAT, which maynot provide RAN assistance information to the UE 115-c. In thesesituations, the UE 115-c may have access to alternative information thatmay be utilized to make determinations related to the offloading of oneor more PDN connections. For example, the UE 115-c may utilize the lastset of assistance information received.

For example, and still referring to FIG. 5, in one embodiment, thethreshold module 505 of the UE 115-c may determine that RAN assistanceinformation is unavailable, where the RAN assistance informationincludes a first set of thresholds for switching a PDN connection of theUE from a WLAN back to a WWAN. The threshold module 505 may access asecond, alternative set of thresholds, based at least in part on thedetermination that no current, UE 115-c specific RAN assistanceinformation is available. The threshold module 505 may then determinewhether or not to switch the PDN connection of the UE 115-c from theWLAN back to the WWAN based at least in part on the second set ofthresholds.

Still referring to FIG. 5, in one embodiment, the UE 115-c may receivean offloadability indicator corresponding to a PDN connection of themobile device, the offloadability indicator being received irrespectiveof a mode of operation of the UE 115-c. The UE 115-c (e.g., thethreshold module 505) may utilize the received offloadability indicatorto determine whether to offload the PDN connection from a WWAN to a WLANif and when the UE 115-c is currently receiving RAN assistanceinformation or when the UE 115-c has access to a set of thresholds foruse in making an offloading determination. If, however, the UE 115-c isnot contemporaneously receiving RAN assistance information and/or doesnot have access to a set of thresholds for use in making anoffloadability determination, the UE 115-c may disregard the receivedoffloadability indicator. The UE 115-c may use the receivedoffloadability indicator(s), together with the received RAN rules andRAN assistance information (e.g., thresholds) in determining whether aPDN connection should be offloaded to a WLAN, or maintained/switchedback to a WWAN.

The transmitter 320 may transmit one or more signals received from othercomponents of the UE 115-c. For example, the transmitter 320 maytransmit data on an uplink connection to an access point 105, 140.

FIG. 6 shows a block diagram 600 of a UE 115-d that may offload one ormore PDN connections to a WLAN in accordance with various embodiments.The UE 115-d in FIG. 6 may be, for example, one of the UEs 115, 115-a,115-b, 115-c shown in FIG. 1-2 or 5, and may be an example of one ormore aspects of the UE 115-c described with reference to FIG. 5. The UE115-d shown in FIG. 6 includes a receiver 310, threshold module 505-a,and a transmitter 320. The UE 115-d may also include a processor. Eachof these components may be in communication with each other. Thethreshold module 505-a in FIG. 6 includes a default threshold module605, a previous threshold module 610, a SIB threshold module 615, and anoffloadability indicator module 620.

The components of the UE 115-d may, individually or collectively, beimplemented with one or more application-specific integrated circuits(ASICs) adapted to perform some or all of the applicable functions inhardware. Alternatively, the functions may be performed by one or moreother processing units (or cores), on one or more integrated circuits.In other embodiments, other types of integrated circuits may be used(e.g., Structured/Platform ASICs, Field Programmable Gate Arrays(FPGAs), and other Semi-Custom ICs), which may be programmed in anymanner known in the art. The functions of each unit may also beimplemented, in whole or in part, with instructions embodied in amemory, formatted to be executed by one or more general orapplication-specific processors.

The receiver 310 may receive information such as packets, user data,and/or control information associated with various information channels(e.g., control channels, data channels, etc.), as described above withreference to FIG. 5. Information may be passed on to the thresholdmodule 505-a, and to other components of the UE 115-d. The thresholdmodule 505-a may be configured to perform the operations described abovewith reference to the threshold module 505 shown in FIG. 5. Thetransmitter 320 may transmit the one or more signals received from othercomponents of the UE 115-d, as described above with reference to FIG. 5.

The default threshold module 605, previous threshold module 610, SIBthreshold module 615, and offloadability indicator module 620 may all beconfigured to receive, analyze, and/or provide information for use indetermining whether a PDN connection should be offloaded to an availableWLAN, should be switched back to a WWAN, or should be maintained on aWWAN or WLAN. The default threshold module 605, previous thresholdmodule 610, and SIB threshold module 615, in particular, may be used toprovide alternate thresholds in place of current, UE-specific RANassistance information if such information is not available to the UE115-d. The default threshold module 605, for example, may store adefault set of thresholds preconfigured in the UE 115-d. This defaultset of thresholds may be set at sufficiently high (or low) values inorder to reduce the likelihood that the UE 115-f will switch a PDNconnection back to the WLAN/WWAN from the WWAN/WLAN within apredetermined time period. For example, the default set of thresholdsmay be stringently set such that a PDN connection is unlikely (e.g.,less than 5% chance) of switching back to a WLAN connection within apredetermined time (e.g., 1 second) of switching to a WWAN connection.Doing so may help avoid “ping-ponging” between the WLAN and WWAN for thePDN connection.

The previous threshold module 610 may store a set of thresholdspreviously received by the UE 115-d; for example, RAN assistancethresholds previously sent by an access point. The set of previouslyreceived thresholds may include an expiration time and/or the previousthreshold module 610 may only retain and/or use previously receivedthresholds for a certain period of time before discarding them. The SIBthreshold module 615 may receive and process a broadcast set ofthresholds (e.g., from SIB broadcast module 410 in FIG. 4) provided by aprospective WWAN, with the broadcast set of thresholds not beingspecific to the UE 115-d or any UE 115.

The offloadability indicator module 620 may be configured to receive,store, and/or process offloadability indicator (e.g., received from theNAS broadcast module 415 in FIG. 4). For example, the offloadabilityindicator module 620 may store a received offloadability indicator forlater use even if the UE 115-d is not contemporaneously receiving RANassistance information and/or does not have access to any thresholds foruse in making an offloading determination. In this example, theoffloadability indicator module 620 may be configured to later utilizethe stored offloadability indicator to determine whether to offload aPDN connection to a WLAN when the UE 115-d switched to a RAT that doesprovide RAN assistance thresholds to the UE 115-d.

In some embodiments, an offloadability indicator received by theoffloadability indicator module 620 may be specific to the RAT overwhich the offloadability indicator was received, and an updatedoffloadability indicator may be provided by the WWAN when the UE 115-dswitches to a different RAT. In other embodiments, an offloadabilityindicator may be generic to a plurality of different RATs such that theWWAN does not need to send a new offloadability indicator when the UE115-d switches to a new RAT. In order to enable the reuse of anoffloadability indicator among different RATs, the offloadabilityindicator module 620 may store the generic offloadability indicator,even if the RAT over which the indicator was received does not provideRAN assistance information. Optionally, the offloadability indicatormodule 620 may also store an expiration associated with anyoffloadability indicators stored for later use. Again, as describedabove, the UE 115-d may use the received offloadability indicator(s),together with the received RAN rules and RAN assistance information(e.g., thresholds) in determining whether a PDN connection should beoffloaded to a WLAN, or maintained/switched back to a WWAN. In someembodiments, the various thresholds available to the UE 115-d may beused in a hierarchical manner. For example, if live RAN assistanceinformation is available, the UE 115-d may use that information inmaking PDN connection offloading determinations. If not available, theUE 115-d may use a second-best set of thresholds, such as thresholdsthat were previously (recently) received by the UE 115-d. If those arenot available, the UE 115-d may use generic thresholds broadcast in theSIB broadcast message, and if those are not available, may use thedefault threshold values preconfigured in the UE 115-d. It will beunderstood that the hierarchy just described is just one example andthat any hierarchy of threshold data may be used.

FIG. 7 shows a block diagram of a system 700 for use in offloading oneor more PDN connections in accordance with various embodiments. System700 includes UEs 115-e-1, 115-e-2, which may be examples of the UEs 115,115-a, 115-b, 115-c, 115-d in FIGS. 1-2 and 5-6. System 700 alsoincludes a base station 105-g, which may be an example of the basestations 105, 105-a, 105-b, 105-c, 105-d, 105-e, 105-f in FIGS. 1-4.System 700 also includes a WLAN AP 140-b, which may be an example of theWLAN APs 140, 140-a in FIGS. 1-2.

The UE 115-e-1 shown in FIG. 7 includes antenna(s) 740, a transceivermodule 735, a processor module 705, and memory 715 (including software(SW) 720), which each may communicate, directly or indirectly, with eachother (e.g., via one or more buses 745). The transceiver module 735 maybe configured to communicate bi-directionally, via the antenna(s) 740and/or one or more wireless communication links, with one or more basestations 105-g, one or more WLAN APs 140-b, or other nodes, as describedabove. The transceiver module 735 may include a modem configured tomodulate the packets and provide the modulated packets to the antenna(s)740 for transmission, and to demodulate packets received from theantenna(s) 740. While the UE 115-e-1 may include a single antenna 740 insome embodiments, the UE 115-e-1 may alternatively have multipleantennas 740 capable of concurrently transmitting and/or receivingmultiple wireless transmissions. The transceiver module 735 may thus becapable of concurrently communicating with one or more base stations105-g and/or one or more WLAN APs 140-b.

The memory 715 may include random access memory (RAM) and/or read-onlymemory (ROM). The memory 715 may store computer-readable,computer-executable software/firmware code 720 containing instructionsthat are configured to, when executed, cause the processor module 705 toperform various functions described herein (e.g., make and/or executeoffloading determinations). Alternatively, the software/firmware code720 may not be directly executable by the processor module 705 but beconfigured to cause a computer (e.g., when compiled and executed) toperform functions described herein. The processor module 705 may includean intelligent hardware device, e.g., a central processing unit (CPU), amicrocontroller, an application-specific integrated circuit (ASIC), etc.may include random access memory (RAM) and read-only memory (ROM). Thememory 715 may include a data cache, which may store alternativethreshold information, as described above with reference to FIG. 6.

The UE 115-e-1 also includes default threshold module 605, previousthreshold module 610, SIB threshold module 615, and offloadabilityindicator module 620, which may be examples of the respective defaultthreshold module 605, previous threshold module 610, SIB thresholdmodule 615, and offloadability indicator module 620 shown in FIG. 6 anddescribed above, and may together form a threshold module, which may bean example of the threshold module 505 shown and described above withreference to FIG. 5.

FIG. 8 shows a diagram of a system 800 for use in offloading one or morePDN connections in accordance with various embodiments. System 800includes base stations 105-h, 805-a-1, 805-a-2, which may be examples ofthe base stations 105, 105-a, 105-b, 105-c, 105-d, 105-e, 105-f, 105-gdescribed above. System 800 also includes a UE 115-f, which may be anexample of the UEs 115, 115-a, 115-b, 115-c, 115-d, 115-e describedabove.

The base station 105-h may include antenna(s) 845, a transceiver module850, memory 880, and a processor module 870, which each may be incommunication, directly or indirectly, with each other (e.g., over oneor more buses). The transceiver module 850 may be configured tocommunicate bi-directionally, via the antenna(s) 845, with the UE 115-fas well as other UEs (not shown in FIG. 8). The transceiver module 850(and/or other components of the base station 105-d) may also beconfigured to communicate bi-directionally with one or more networks. Insome cases, the base station 105-h may communicate with the core network130-a and/or controller 820—through network communications module 875.Base station 105-h may be an example of an eNodeB base station, a HomeeNodeB base station, a NodeB base station, and/or a Home NodeB basestation. Controller 820 may be integrated into base station 105-h insome cases, such as with an eNodeB base station.

Base station 105-h may also communicate with other base stations 105,such as base station 805-a-1 and base station 805-a-2. Each of the basestations 105, 805-a-1, 805-a-2 may communicate with one or more UEsusing different wireless communications technologies, such as differentRadio Access Technologies. In some cases, base station 105-h maycommunicate with other base stations such as 805-a-1 and/or 805-a-2utilizing base station communication module 865. In some embodiments,base station communication module 865 may provide an X2 interface withinan LTE wireless communication technology to provide communicationbetween some of the base stations 105-h, 805-a-1, 805-a-2. In someembodiments, base station 105-h may communicate with other base stationsthrough controller 820 and/or core network 130-b.

The memory 880 may include random access memory (RAM) and read-onlymemory (ROM). The memory 880 may also store computer-readable,computer-executable software code 885 containing instructions that areconfigured to, when executed, cause the processor module 870 to performvarious functions described herein (e.g., call processing, databasemanagement, message routing, etc.). Alternatively, the software code 885may not be directly executable by the processor module 870 but may beconfigured to cause the computer, e.g., when compiled and executed, toperform functions described herein.

The processor module 870 may include an intelligent hardware device,e.g., a central processing unit (CPU), a microcontroller, anapplication-specific integrated circuit (ASIC), etc. The transceivermodule 850 may include a modem configured to modulate the packets andprovide the modulated packets to the antenna(s) 845 for transmission,and to demodulate packets received from the antenna(s) 845. While someexamples of the base station 105-h may include a single antenna 845, thebase station 105-h preferably includes multiple antennas 845 formultiple links which may support carrier aggregation. For example, oneor more links may be used to support macro communications with UEs 115.

According to the architecture of FIG. 8, the base station 105-h mayfurther include a communications management module 860. Thecommunications management module 860 may manage communications withother base stations 105. By way of example, the communicationsmanagement module 860 may be a component of the base station 105-h incommunication with some or all of the other components of the basestation 105-h via a bus. Alternatively, functionality of thecommunications management module 860 may be implemented as a componentof the transceiver module 850, as a computer program product, and/or asone or more controller elements of the processor module 870.

The base station 105-h in FIG. 8 also includes RFSP Module 405, SIBbroadcast module 410, and NAS broadcast module 415, which may beexamples of the respective RFSP Module 405, SIB broadcast module 410,and NAS broadcast module 415 shown in FIG. 4 and described above, andmay together form an offloading module, which may be an example of theoffloading module 315 shown and described above with reference to FIG.3.

FIG. 9 illustrates a diagram 900 of a signaling flow between a UE 115-gand a base station 105-i for use in offloading one or more PDNconnections in accordance with various embodiments. The UE 115-g may bean example of the UEs 115, 115-a, 115-b, 115-c, 115-d, 115-e, 115-fdescribed above, and the base station 105-i may be an example of thebase stations 105, 105-a, 105-b, 105-c, 105-d, 105-e, 105-f, 105-g,105-h described above. The UE 115-g may transmit a PDN connectionrequest 905 to the base station 105-i indicating that the UE 115-gdesires to initiate a PDN connection. In response, the base station105-i sends PDN connection parameters 910 to the UE 115-g, which mayenable the UE 115-g and base station 105-i to initiate the PDNconnection.

The base station may also send, via NAS signaling, an offloadabilityindicator 915 to the UE 115-g as described above—for example, anoffloadability status indicator may be provided in a bearer contextstatus IE in the accept message to the PDN connection activationrequest. In some instances, the offloadability indicator associated withthat PDN connection may be sent to the UE 115-g upon initiation of thePDN connection, whereas in other embodiments the offloadabilityindicator may be sent later. In some embodiments, an updatedoffloadability indicator may later be sent to the UE 115-g in responseto some change, such as if the UE 115-g switches to a different RATconnection with the base station 105-i, if there are too manyconnections or too much traffic demand on a particular WWAN or WLAN,etc. The updated offloadability indicator may be provided in an updatedbearer context status in a NAS message to the UE 115-g in someembodiments. In some examples, the messages 905, 910, and 915 may besent and/or received between a Serving GPRS Support Node (SGSN) and aMobility Management Entity (MME).

In some embodiments, the base station 105-i always sends theoffloadability indicator—that is, the base station 105-i sends theoffloadability indicator irrespective of a mode of communication betweenthe UE 115-g and base station 105-i. In these embodiments, even if theUE 115-g is in an A/Gb mode of operation, the offloadability indicatormay still be sent, and the UE 115-g may simply store the indicator forlater use (i.e., in case the UE 115-g later connects to base station105-i in an Iu or LTE mode of operation). In other embodiments, however,the base station 105-i may first determine a mode of operationassociated with each UE 115-g, and may only send the offloadabilityindicators associated with respective PDN connections if the UE is in acertain mode of operation—such as a mode of operation in which WLANoffloading is permitted.

The base station 105-i may also send RAN rules 920 and RAN assistanceinformation 925 to the UE 115-g using RAN signaling in some embodiments.As described above, even if the UE 115-g cannot offload any PDNconnections, the UE 115-g may store the RAN rules and/or RAN assistanceinformation received from the base station 105-i for later use.

FIGS. 10A, 10B, 11A, 11B, 12A, 12B, 13A, 13B, 14A, 14B provide examplesof how one or more PDN connections of a UE 115-h may be offloaded froman eNB base station 105-j to a WLAN AP 140-c, and FIGS. 15A and 15Bprovide examples of how one or more PDN connections can be moved from aneNB/LTE base station 105-j to a non-LTE base station 105-k, and therepercussions of such a move.

Referring first to FIG. 10A, a diagram illustrates a configuration of awireless communication system 1000-a in which a UE 115-h may have a CSFBPDN Connection A and an Internet PDN Connection B with a eNB basestation 105-j. The PDN Connections A and B may connect to different APNsover the WWAN associated with the eNB base station 105-j. Each of theeNB base station 105-j and the WLAN AP 140-c may have a connection to anEPC 130-c, which may in turn have a connection to PDNs 235-a. Thewireless communication system 1000-a, UE 115-h, eNB base station 105-j,WLAN AP 140-c, EPC 130-a, and PDNs 235-a may be examples of one or moreaspects of respective communications systems, UEs, base stations, WLANAps, EPCs, and PDNs described above.

At some point during operation of the wireless communications system1000-a, a triggering event may cause one of the PDN connections to beoffloaded from the eNB 105-j to the WLAN AP 140-c. For example, thetriggering event may include a decision by an access management moduleof the UE 115-h that a WLAN is preferred over the LTE WWAN. In othercases, the triggering event may include activity (e.g., a request) of anapplication running on the UE 115-h or the user of the UE 115-h. In FIG.10A, the triggering event is a request to move traffic via NSWO to theWLAN AP.

FIG. 10B is a diagram illustrating a configuration of a wirelesscommunications system 1000-b that may result from the NSWO triggeringevent described above. In the configuration, the UE 115-h maintains thePDN Connection A for the CSFB with the eNB 105-j, but the traffic forthe Internet application on the UE 115-h is moved, via NSWO to the WLANAP 140-c. In this example, the UE 115-h may not detach from the LTEWWAN, because of the remaining PDN Connection A for CSFB. As such, theremay be no interruption of voice services and there similarly may be noissue with the UE 115-h continuing to receive RAN assistance informationfrom the LTE WWAN.

FIGS. 11A and 11B are diagrams illustrating configurations of wirelesscommunications systems 1100-a, 1100-b that are similar to the systems1000-a, 1000-b shown in FIGS. 10A and 10B, except that PDN Connection A(CSFB) has been designated as non-offloadable and PDN Connection B(Internet) has been designated as offloadable. Also, the triggeringevent in FIGS. 11A and 1 lB may cause the PDN Connection B to beoffloaded to the WLAN AP 140-c via a PDN handover (instead of via NSWO).However, because there is still an active PDN connection (Connection A)from the UE 115-h to the LTE WWAN, there may be no voice servicesinterruption and no issue with the UE 115-h continuing to receive RANassistance information from the LTE WWAN.

FIGS. 12A and 12B are diagrams illustrating configurations of wirelesscommunications systems 1200-a, 1200-b that are similar to the systems1100-a, 1100-b shown in FIGS. 11A and 11B, except that in FIGS. 12A and12B, both PDN Connection A and PDN Connection B have been designated asoffloadable. After a triggering event causing PDN Connections A and B tobe offloaded to the WLAN AP 140-c via a PDN handover, the UE 115-h maydetach from the LTE WWAN of the eNB 105-j. In this instance, if the UE115-h does not quickly reattach to a WWAN, there may be an interruptionof one or both of CS based services and/or receiving RAN assistanceinformation for facilitating the eventual switch back to the WWAN of thePDN traffic offloaded to the WLAN AP 140-c. As such, and as describedabove, the UE 115-h may receive RFSP index information from, forexample, the eNB base station 105-j which may cause the UE 115-h to campon a non-LTE base station 105-k, which may include a UTRAN or GERAN RAT.It will be appreciated that while the non-LTE base station 105-k isillustrated in FIGS. 12A and 12B as being physically separate from theLTE eNB 105-j, in some embodiments, the eNB 105-j and non-LTE BS 105-kmay be one and the same base station, but may use different RATs intheir respective WWAN services.

FIGS. 13A and 13B are diagrams illustrating configurations of wirelesscommunications systems 1300-a, 1300-b that are similar to the systems1100-a, 1100-b shown in FIGS. 11A and 11B, except that in FIGS. 13A and13B, VoLTE is used for voice services (i.e., instead of CSFB), and thePDN Connection A for VoLTE has been designated as non-offloadable. inthis example, because there is still an active PDN connection(Connection A) from the UE 115-h to the LTE WWAN, there may be no voiceservices interruption and no issue with the UE 115-h continuing toreceive RAN assistance information from the LTE WWAN even if the PDNConnection B is offloaded to the WLAN AP.

FIGS. 14A and 14B are diagrams illustrating configurations of wirelesscommunications systems 1400-a, 1400-b that are similar to the systems1200-a, 1200-b shown in FIGS. 12A and 12B and the systems 1300-a, 1300-bshown in FIGS. 13A and 13B, except that in FIGS. 14A and 14B, VoLTE isused for voice services and both PDN Connection A (VoLTE) and PDNConnection B (Internet) have been designated as offloadable.Accordingly, after a triggering event causing PDN Connections A and B tobe offloaded to the WLAN AP 140-c via a PDN handover, the UE 115-h maydetach from the LTE WWAN of the eNB 105-j. In this instance, if the UE115-h does not quickly reattach to a WWAN, there may be an interruptionof receiving RAN assistance information for facilitating the eventualswitch back to the WWAN of the PDN traffic offloaded to the WLAN AP140-c, for example. As such, and as described above, the UE 115-h mayreceive RFSP index information from, for example, the eNB base station105-j which may cause the UE 115-h to camp on a non-LTE base station105-k, which may include a UTRAN or GERAN RAT.

FIGS. 15A and 15B are diagrams illustrating configurations of wirelesscommunications systems 1500-a, 1500-b that are similar to the systems1000-a, 1000-b shown in FIGS. 10A and 10B, except that in FIGS. 15A and15B, PDN Connections A and B are offloaded to a non-LTE WWAN 105-kinstead of to a WLAN AP. In this scenario, an offloadability indicatorreceived when the UE 115-h was connected to the LTE WWAN 105-j may havebeen stored and may still be used together with RAN assistanceinformation received from the non-LTE BS 105-k to make offloadingdeterminations, as described above.

FIG. 16 shows a flowchart 1600 illustrating a method of switching a PDNconnection from a WLAN to a WWAN in accordance with various embodiments.The functions of flowchart 1600 may be implemented by any of the UEs 115described above.

At block 1605, the UE may determine that RAN assistance information isunavailable, where the RAN assistance information includes a first setof thresholds for switching a specific PDN connection of the UE from aWLAN back to a WWAN. At block 1610, the UE may access a second,alternative set of thresholds based at least in part on the determiningof block 1605 (as described above), and at block 1615, the UE may switchthe PDN connection from the WLAN back to the WWAN based at least in parton the second set of thresholds accessed at block 1610.

It should be noted that the method of flowchart 1600 is just oneimplementation of the operations of the method, and that the steps maybe rearranged or otherwise modified such that other implementations arepossible.

FIG. 17 shows a flowchart 1700 illustrating a method of utilizing anoffloadability indicator to determine whether to offload a PDNconnection from a WWAN to a WLAN in accordance with various embodiments.The functions of flowchart 1700 may be implemented by any of the UEs 115described above.

At block 1705, the UE may receive an offloadability indicatorcorresponding to a PDN connection of the UE, the offloadabilityindicator being received by the UE irrespective of a mode of operationof the UE. At block 1710, the UE may utilize the offloadabilityindicator received at block 1705 to determine whether to offload the PDNconnection from the WWAN to the WLAN, the offloadability indicator beingutilized when the UE receives RAN assistance information or has accessto a set of thresholds related to offloading the PDN connection from theWWAN to the WLAN. At block 1715, the UE may disregard the offloadabilityindicator received at block 1705 when the UE is not receiving RANassistance information or does not have access to a set of thresholdsfor use in making an offloading determination.

It should be noted that the method of flowchart 1700 is just oneimplementation of the operations of the method, and that the steps maybe rearranged or otherwise modified such that other implementations arepossible.

FIG. 18 shows a flowchart 1800 illustrating a method of sendingoffloadability indicators in accordance with various embodiments. Thefunctions of flowchart 1600 may be implemented by any of the basestations 105 described above.

At block 1805, the base station may determine a mode of operation of aUE, and at block 1810, the base station may send an offloadabilityindicator corresponding to a PDN connection based at least in part onthe determination.

It should be noted that the method of flowchart 1800 is just oneimplementation of the operations of the method, and that the steps maybe rearranged or otherwise modified such that other implementations arepossible.

The detailed description set forth above in connection with the appendeddrawings describes exemplary embodiments and does not represent the onlyembodiments that may be implemented or that are within the scope of theclaims. The term “exemplary” used throughout this description means“serving as an example, instance, or illustration,” and not “preferred”or “advantageous over other embodiments.” The detailed descriptionincludes specific details for the purpose of providing an understandingof the described techniques. These techniques, however, may be practicedwithout these specific details. In some instances, well-known structuresand devices are shown in block diagram form in order to avoid obscuringthe concepts of the described embodiments.

Information and signals may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the above description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA) or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. Ageneral-purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, multiple microprocessors, one or moremicroprocessors in conjunction with a DSP core, or any other suchconfiguration.

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope and spirit of the disclosure and appended claims. For example,due to the nature of software, functions described above can beimplemented using software executed by a processor, hardware, firmware,hardwiring, or combinations of any of these. Features implementingfunctions may also be physically located at various positions, includingbeing distributed such that portions of functions are implemented atdifferent physical locations. Also, as used herein, including in theclaims, “or” as used in a list of items (for example, a list of itemsprefaced by a phrase such as “at least one of” or “one or more of”)indicates a disjunctive list such that, for example, a list of “at leastone of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., Aand B and C).

Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage medium may be anyavailable medium that can be accessed by a general purpose or specialpurpose computer. By way of example, and not limitation,computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or otheroptical disk storage, magnetic disk storage or other magnetic storagedevices, or any other medium that can be used to carry or store desiredprogram code means in the form of instructions or data structures andthat can be accessed by a general-purpose or special-purpose computer,or a general-purpose or special-purpose processor. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,include compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

Techniques described herein may be used for various wirelesscommunications systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, andother systems. The terms “system” and “network” are often usedinterchangeably. A CDMA system may implement a radio technology such asCDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0 and Aare commonly referred to as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) iscommonly referred to as CDMA2000 1×EV-DO, High Rate Packet Data (HRPD),etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. ATDMA system may implement a radio technology such as Global System forMobile Communications (GSM). An OFDMA system may implement a radiotechnology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA),IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, etc.UTRA and E-UTRA are part of Universal Mobile Telecommunication System(UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are newreleases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, andGSM are described in documents from an organization named “3rdGeneration Partnership Project” (3GPP). CDMA2000 and UMB are describedin documents from an organization named “3rd Generation PartnershipProject 2” (3GPP2). The techniques described herein may be used for thesystems and radio technologies mentioned above as well as other systemsand radio technologies.

The previous description of the disclosure is provided to enable aperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Throughout this disclosure the term “example” or“exemplary” indicates an example or instance and does not imply orrequire any preference for the noted example. Thus, the disclosure isnot to be limited to the examples and designs described herein but is tobe accorded the widest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method for wireless communication, comprising:establishing, by a mobile device, a packet data network (PDN) connectionvia a first wireless wide area network (WWAN); offloading the PDNconnection from the first WWAN to a wireless local area network (WLAN);determining to camp on a second WWAN based at least in part on all PDNconnections of the mobile device being offloaded to the WLAN and acellular radio of the mobile device being in idle mode; determining, bythe mobile device, that Radio Access Network (RAN) assistanceinformation is unavailable, the RAN assistance information comprising afirst set of thresholds for switching the PDN connection of the mobiledevice from the WLAN to the first WWAN; accessing a second set ofthresholds for switching one or more PDN connections of the mobiledevice to the first WWAN based at least in part on the determinationthat RAN assistance information is unavailable, wherein the second setof thresholds comprise a default set of thresholds preconfigured in themobile device; and switching the one or more PDN connections of themobile device from the WLAN to the first WWAN based at least in part onthe second set of thresholds.
 2. The method of claim 1, wherein thesecond set of thresholds comprises one or more of a connection qualityindication (CQI) associated with the WLAN or the first WWAN, an Internetaccessibility indication associated with the WLAN and/or the first WWAN,a signal strength indication associated with the WLAN and/or the firstWWAN, and/or a power level associated with the mobile device.
 3. Themethod of claim 1, wherein the default set of thresholds is set tovalues sufficiently high in order to reduce a likelihood that the mobiledevice will switch the one or more PDN connections back to the WLANwithin a predetermined time period after switching to the first WWAN. 4.The method of claim 1, wherein the second set of thresholds comprises abroadcast set of thresholds provided by the first WWAN, the broadcastset of thresholds being unspecific to the mobile device.
 5. The methodof claim 4, further comprising: receiving the broadcast set ofthresholds via a system information block (SIB) from the first WWAN. 6.The method of claim 1, wherein determining to camp on the second WWANcomprises receiving an indication which prioritizes the mobile devicecamping on the second WWAN over camping on the first WWAN.
 7. The methodof claim 1, wherein the second WWAN is one of Global Systems for Mobilecommunications (GSM) Enhanced Data Rates for GSM Evolution (EDGE) radioaccess network (GERAN) or Universal Mobile Telecommunications System(UMTS) Terrestrial Radio Access Network (UTRAN) in order to reduce aprobability of missing a circuit switched (CS) call at the mobiledevice.
 8. The method of claim 1, wherein the second WWAN is UniversalMobile Telecommunications System (UMTS) Terrestrial Radio Access Network(UTRAN) in order to allow the mobile device to continue receiving RANassistance information related to the first WWAN.
 9. An apparatus forwireless communication, comprising: a processor; memory in electroniccommunication with the processor, the memory embodying instructions, theinstructions being executable by the processor to: establish, by amobile device, a packet data network (PDN) connection via a firstwireless wide area network (WWAN); offload the PDN connection from thefirst WWAN to a wireless local area network (WLAN); determine to camp ona second WWAN based at least in part on all PDN connections of themobile device being offloaded to the WLAN and a cellular radio of themobile device being in idle mode; determine, by the mobile device, thatRadio Access Network (RAN) assistance information is unavailable, theRAN assistance information comprising a first set of thresholds forswitching the PDN connection of the mobile device from the WLAN to thefirst WWAN; access a second set of thresholds for switching one or morePDN connections of the mobile device to the first WWAN based at least inpart on the determination that RAN assistance information isunavailable, wherein the second set of thresholds comprise a default setof thresholds preconfigured in the mobile device; and switch the one ormore PDN connections of the mobile device from the WLAN to the firstWWAN based at least in part on the second set of thresholds.
 10. Theapparatus of claim 9, wherein the second set of thresholds comprises oneor more of a connection quality indication (CQI) associated with theWLAN or the first WWAN, an Internet accessibility indication associatedwith the WLAN and/or the first WWAN, a signal strength indicationassociated with the WLAN and/or the first WWAN, and/or a power levelassociated with the apparatus.
 11. The apparatus of claim 9, wherein thedefault set of thresholds is set to values sufficiently high in order toreduce a likelihood that the apparatus will switch the one or more PDNconnections back to the WLAN within a predetermined time period afterswitching to the first WWAN.
 12. The apparatus of claim 9, wherein thesecond set of thresholds comprises a broadcast set of thresholdsprovided by the first WWAN, the broadcast set of thresholds beingunspecific to the apparatus.
 13. The apparatus of claim 12, wherein theinstructions are further executable by the processor to: receive thebroadcast set of thresholds via a system information block (SIB) fromthe first WWAN.
 14. A non-transitory computer-readable medium storinginstructions executable by a processor to cause a wireless communicationapparatus to: establish, by a mobile device, a packet data network (PDN)connection via a first wireless wide area network (WWAN); offload thePDN connection from the first WWAN to a wireless local area network(WLAN); determine to camp on a second WWAN based at least in part on allPDN connections of the mobile device being offloaded to the WLAN and acellular radio of the mobile device being in idle mode; determine, bythe mobile device, that Radio Access Network (RAN) assistanceinformation is unavailable, the RAN assistance information comprising afirst set of thresholds for switching the PDN connection of the mobiledevice from the WLAN to the first WWAN; access a second set ofthresholds for switching one or more PDN connections of the mobiledevice to the first WWAN based at least in part on the determinationthat RAN assistance information is unavailable, wherein the second setof thresholds comprise a default set of thresholds preconfigured in themobile device; and switch the one or more PDN connections of the mobiledevice from the WLAN to the first WWAN based at least in part on thesecond set of thresholds.
 15. The non-transitory computer-readablemedium of claim 14, wherein the second set of thresholds comprises oneor more of a connection quality indication (CQI) associated with theWLAN or the first WWAN, an Internet accessibility indication associatedwith the WLAN or the first WWAN, a signal strength indication associatedwith the WLAN and/or the first WWAN, and/or a power level associatedwith the apparatus.